Private network peering in virtual network environments

ABSTRACT

Methods and apparatus for private network peering in virtual network environments in which peerings between virtual client private networks on a provider network may be established by clients via an API to a peering service. The peering service and API 104 may allow clients to dynamically establish and manage virtual network transit centers on the provider network at which virtual ports may be established and configured, virtual peerings between private networks may be requested and, if accepted, established, and routing information for the peerings may be specified and exchanged. Once a virtual peering between client private networks is established, packets may be exchanged between the respective client private networks via the peering over the network substrate according to the overlay network technology used by the provider network, for example an encapsulation protocol technology.

This application is a continuation of U.S. patent application Ser. No.14/109,535, filed Dec. 17, 2013, now U.S. Pat. No. 9,807,057, which ishereby incorporated by reference herein in its entirety.

BACKGROUND

Many companies and other organizations operate computer networks thatinterconnect numerous computing systems to support their operations,such as with the computing systems being co-located (e.g., as part of alocal network) or instead located in multiple distinct geographicallocations (e.g., connected via one or more private or publicintermediate networks). For example, data centers housing significantnumbers of interconnected computing systems have become commonplace,such as private data centers that are operated by and on behalf of asingle organization, and public data centers that are operated byentities as businesses to provide computing resources to customers orclients. Some public data center operators provide network access,power, and secure installation facilities for hardware owned by variousclients, while other public data center operators provide “full service”facilities that also include hardware resources made available for useby their clients. However, as the scale and scope of typical datacenters has increased, the tasks of provisioning, administering, andmanaging the physical computing resources have become increasinglycomplicated.

The advent of virtualization technologies for commodity hardware hasprovided benefits with respect to managing large-scale computingresources for many clients with diverse needs, allowing variouscomputing resources to be efficiently and securely shared by multipleclients. For example, virtualization technologies may allow a singlephysical computing machine to be shared among multiple users byproviding each user with one or more virtual machines hosted by thesingle physical computing machine, with each such virtual machine beinga software simulation acting as a distinct logical computing system thatprovides users with the illusion that they are the sole operators andadministrators of a given hardware computing resource, while alsoproviding application isolation and security among the various virtualmachines. Furthermore, some virtualization technologies are capable ofproviding virtual resources that span two or more physical resources,such as a single virtual machine with multiple virtual processors thatspans multiple distinct physical computing systems. As another example,virtualization technologies may allow data storage hardware to be sharedamong multiple users by providing each user with a virtualized datastore which may be distributed across multiple data storage devices,with each such virtualized data store acting as a distinct logical datastore that provides users with the illusion that they are the soleoperators and administrators of the data storage resource.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example provider network environment in whichembodiments of the methods and apparatus for private network peering invirtual network environments may be implemented.

FIG. 2 is a high-level flowchart of a method for private network peeringin virtual network environments, according to at least some embodiments.

FIGS. 3A through 3C illustrate example route tables for a virtualpeering between client private networks on a provider network, accordingto at least some embodiments.

FIG. 4 illustrates routing packets between client private networks overa virtual peering path of an overlay network implemented in an exampleprovider network environment, according to at least some embodiments.

FIG. 5 illustrates a peering service and API in a provider networkenvironment, according to at least some embodiments.

FIGS. 6A through 6C illustrate example use cases for virtual peeringbetween client private networks in a provider network environment,according to at least some embodiments.

FIGS. 7A and 7B illustrate example configurations for peerings betweenmultiple client private networks, according to at least someembodiments.

FIGS. 8A and 8B illustrate example configurations for virtual networktransit centers between client private networks, according to at leastsome embodiments.

FIG. 9 illustrates an example provider network environment, according toat least some embodiments.

FIG. 10 illustrates an example data center that implements an overlaynetwork on a network substrate using IP tunneling technology, accordingto some embodiments.

FIG. 11 is a block diagram of an example provider network that providesa storage virtualization service and a hardware virtualization serviceto clients, according to at least some embodiments.

FIG. 12 illustrates an example provider network that providesvirtualized private networks to at least some clients, according to atleast some embodiments.

FIG. 13 illustrates subnets and security groups in an example virtualprivate network implementation on a provider network, according to atleast some embodiments.

FIG. 14 is a block diagram illustrating an example computer system thatmay be used in some embodiments.

While embodiments are described herein by way of example for severalembodiments and illustrative drawings, those skilled in the art willrecognize that embodiments are not limited to the embodiments ordrawings described. It should be understood, that the drawings anddetailed description thereto are not intended to limit embodiments tothe particular form disclosed, but on the contrary, the intention is tocover all modifications, equivalents and alternatives falling within thespirit and scope as defined by the appended claims. The headings usedherein are for organizational purposes only and are not meant to be usedto limit the scope of the description or the claims. As used throughoutthis application, the word “may” is used in a permissive sense (i.e.,meaning having the potential to), rather than the mandatory sense (i.e.,meaning must). Similarly, the words “include”, “including”, and“includes” mean including, but not limited to.

DETAILED DESCRIPTION

Various embodiments of methods and apparatus for private network peeringin virtual network environments are described. More specifically,embodiments of methods and apparatus for establishing peerings betweenvirtualized private networks in overlay network environments aredescribed. Embodiments of the methods and apparatus for private networkpeering in virtual network environments may, for example, be implementedin the context of a service provider that provides to clients orcustomers, via an intermediate network such as the Internet, virtualizedresources (e.g., virtualized computing and storage resources)implemented on a provider network of the service provider.

In at least some embodiments, the provider network may implement anoverlay network on a network substrate that may, for example, use anencapsulation protocol technology for communications between entities onthe provider network. In encapsulation protocol technology, networkpackets may be generated by a network packet source (an entity thatgenerates the network packets), wrapped or encapsulated at anencapsulation layer according to an encapsulation protocol to produceencapsulation protocol packets (also referred to herein as encapsulationpackets or network substrate packets). The encapsulation packets maythen be routed over a network or network substrate to a destinationaccording to routing information for the encapsulation packets. Therouting of the encapsulation packets over the network/network substrateaccording to the encapsulation information may be viewed as sending theencapsulation packets via overlay network routes or paths over thenetwork substrate. At the destination, the encapsulation layer removesthe network packets from the encapsulation packets (a process referredto as decapsulation) and provides or sends the network packets to thenetwork packet destination (an entity that consumes the networkpackets).

Client Private Networks in Provider Network Environments

Embodiments of the methods and apparatus for private network peering invirtual network environments may, for example, be implemented in thecontext of a service provider that provides to clients or customers, viaan intermediate network such as the Internet, virtualized resources(e.g., virtualized computing and storage resources) implemented on aprovider network 100 of a service provider, as illustrated in FIG. 1.FIGS. 9 through 13 and the section titled Example provider networkenvironments further illustrate and describe example service providernetwork environments in which embodiments of the methods and apparatusas described herein may be implemented. Referring to FIG. 1, in at leastsome embodiments of a provider network 100, at least some of theresources provided to clients of a service provider via the providernetwork may be virtualized computing resources implemented onmulti-tenant hardware that is shared with other client(s) and/or onhardware dedicated to the particular client. Each virtualized computingresource may be referred to as a resource instance 112. Resourceinstances 112 may, for example, be rented or leased to clients of theservice provider. For example, clients of the service provider(represented in FIG. 1 by client networks 180A and 180B), via externalclient device(s) coupled to the provider network via an intermediatenetwork 150 such as the Internet, may access one or more services 106 ofthe provider network via application programming interfaces (APIs) 108to the services to obtain and configure resource instances 112.

At least some of the resource instances 112 on the provider network 100may be implemented according to hardware virtualization technology thatenables multiple operating systems to run concurrently on a hostcomputer, i.e. as virtual machines (VMs) on the host. A hypervisor, orvirtual machine monitor (VMM), on a host presents the VMs on the hostwith a virtual platform and monitors the execution of the VMs. Each VMmay be provided with one or more private IP addresses; the VMM on arespective host may be aware of the private IP addresses of the VMs onthe host. For further information about hardware virtualizationtechnology on a provider network, see FIG. 10.

Referring to FIG. 1, the provider network 100 may include a networksubstrate that includes networking devices such as routers, switches,network address translators (NATs), and so on, as well as the physicalconnections among the devices. In at least some embodiments, the VMMs orother devices or processes on the network substrate may useencapsulation protocol technology to encapsulate and route networkpackets (e.g., client IP packets) over the network substrate betweenclient resource instances 112 on different hosts within the providernetwork 100. The encapsulation protocol technology may be used on thenetwork substrate to route encapsulated packets (also referred to asnetwork substrate packets) between endpoints on the network substratevia overlay network paths or routes. The encapsulation protocoltechnology may be viewed as providing a virtual network topologyoverlaid on the network substrate. In at least some embodiments, theencapsulation protocol technology may include a mapping service thatmaintains a mapping directory that maps IP overlay addresses (public IPaddresses) to substrate IP addresses (private IP addresses) and that maybe accessed by various processes on the provider network 100 for routingpackets between endpoints on the network substrate. For furtherinformation about a virtual network technology that uses anencapsulation protocol to implement an overlay network on a networksubstrate, see FIGS. 9 through 13.

Referring to FIG. 1, a service provider may provide one or more services106 with APIs 108 that allow clients to provision logically isolatedsections of the provider network in which the clients can launch theirrespective resource instances in a client-defined virtual network,referred to herein as a virtualized private network or client privatenetwork, or as simply a private network. FIG. 1 illustrates two exampleclient private networks 110A and 110B. Via the APIs 108, a client(represented in FIG. 1 by client networks 180A and 180B) may control thevirtual networking environment of the client's private network 110,including but not limited to selecting private IP address ranges,creating subnets, and configuring route tables, network gateways, loadbalancers, routers, and other network functionalities. Via the APIs 108,a client may customize the network configuration of their client privatenetwork 110. For example, as illustrated in FIG. 12, a client can createa public-facing subnet for web servers that has access to the Internet,and may place backend systems such as databases or application serversin a private-facing subnet with no Internet access. Clients may leveragemultiple layers of security, including but not limited to securitygroups and network access control lists (ACLs), to control access toresource instances in each subnet, for example as illustrated in FIG.13.

Note that a given client may establish one, two, or more separateprivate networks 110 on a provider network 100, and that differentclients may each establish private networks 110 on a provider network100. Further note that a client may specify a private IP address spacefor each client private network 110 on the provider network 100, andthat the private IP address spaces of two (or more) client privatenetworks 110 may, but do not necessarily, overlap.

Peering Client Private Networks in Provider Network Environments

In physical network environments, two private data centers may be peeredwith each other via physical cables that are connected or “patched”between the data centers, for example at a transit center or the like. Aborder routing protocol may be used to exchange information about theprivate networks at the data centers (e.g., private network addressranges to be used in the peering). In virtual network environments thatallow clients to provision virtual private networks, for exampleprovider networks 100 as illustrated in FIG. 1, the clients' virtualprivate network(s) 110 are discrete, routed IP containers that arehosted on a provider network 100 and that may be viewed as virtualanalogs to physical data centers. However, conventionally, in suchvirtual network environments, there has been no virtual analog tophysical transit centers at which physical cables between data centersare patched to create a peering between the respective private networksat the data centers.

Embodiments of methods and apparatus for private network peering invirtual network environments are described in which peerings betweenvirtual private networks on a provider network may be established byclients via one or more peering services and API(s) to the service(s).Referring to FIG. 1, the peering service(s) 102 and API(s) 104 may allowclients (represented in FIG. 1 by client networks 180A and 180B) todynamically establish and manage virtual network transit centers on theprovider network 100 at which virtual ports 124 may be established andconfigured, virtual peerings between private networks 110 may berequested and, if accepted, established, and routing information 122(e.g., route tables) for the peerings may be specified and exchanged.Once a virtual peering between two client private networks 110 isestablished on the provider network 100, packets may be exchangedbetween the respective client private networks via the peering over thenetwork substrate according to the overlay network technology used bythe provider network 100, for example an encapsulation protocoltechnology. See FIG. 4 for an example provider network 100 that usesoverlay network technology for packet exchanges on a virtual peeringbetween two client private networks 110.

The peering service(s) 102 and API(s) 104, used with overlay networktechnology on the provider network 100, may enable clients to privatelypeer their virtual private networks 110 on the provider network 100.Note that a single client may use the peering service(s) 102 and API(s)104 to establish private peerings between two or more of the client'sprivate networks 110 on the provider network 100, or two or moredifferent clients may use the peering service(s) 102 and API(s) 104 toestablish private peerings between two or more of the clients' privatenetworks 110. To facilitate peerings between virtual private networks110 on the provider network 100, embodiments may provide at least thefollowing capabilities to clients via API(s) 104 to peering service(s)102 on the provider network 100:

-   -   API-based creation of virtual port(s) from a virtual private        network 110.    -   API-based creation of border routes for a virtual port 104.    -   API-based creation of a peering between two virtual ports.

FIG. 2 is a high-level flowchart of a method for private network peeringin virtual network environments, according to at least some embodiments.The discussion of FIG. 2 refers to FIG. 1, and two clients are given asexamples: client A, corresponding to client network 180A and clientprivate network 110A of FIG. 1, and client B, corresponding to clientnetwork 180B and client private network 110A of FIG. 1. In FIG. 2,client A has established and manages a virtual private network (clientprivate network 110A) on provider network 100 via virtualizationservice(s) 106. As indicated at 200, client A may initiate a peeringrequest by specifying another virtual private network (client privatenetwork 110B) on the provider network 100 to which a peering is desired.In at least some embodiments, client A may access a peering service 102of the provider network 100 via an API 104 to the service 102 to specifyclient private network 110B. In at least some embodiments, client A mayaccess the API 104 via a management console on a client network 180Aexternal to the provider network 100, for example as illustrated in FIG.5. Note that if client A has two or more private networks 110 on theprovider network, the API may allow client A to select client privatenetwork 110A from among a list of the client's private networks 110 asan initiating private network from which a peering to another privatenetwork (the target private network) is to be requested.

In some instances, client private network 110B may be another one ofclient A's private networks 110, and thus selecting the target privatenetwork via the API 104 may involve selecting client private network110B from client A's list of private networks 110. However, clientprivate network 110B may instead belong to a different client (e.g.,client B) of the provider network 100. (Note that client B may be adifferent department or division of an entity than client A, or may be aseparate and distinct entity). In at least some embodiments of aprovider network 100, clients typically are not aware of and cannot orare not allowed to directly access information about other clients'private network implementations 110 on the provider network 100. Thus,in cases where a client wants to establish a peering from a privatenetwork of the client to another client's private network on theprovider network, initiating the virtual peering from the client'sprivate network to the other client's private network (e.g., fromprivate network 110A of client A to private network 110B of client B)may require a relationship and/or agreement between the clients suchthat the “target” client (e.g., client B) grants permission to theinitiating client (e.g., client A) to access information about andinitiate the peering to the target client's private network. In otherwords, the peering may be initiated and established according to and asa result of an out-of-band negotiation and agreement between the twoclients. In at least some embodiments, in granting permission for apeering, the target client (e.g., client B) may provide information tothe initiating client (e.g., client A) that enables the initiatingclient to view and access at least a basic representation of and/orbasic information about the target client's private network (e.g.,private network 110B) via the API 104 to the peering service 102 on theinitiating client's management console. This provided information may,for example, include an identifier unique to the target client (clientB) and/pr an identifier of the target client's private network 110B towhich client A wants to establish a peering from private network 110A.In at least some embodiments, the clients may exchange security tokens,e.g. public/private key encrypted tokens, that may be used via the API104 to the peering service 102 to securely establish identities betweenthe client private networks 110 when initiating and accepting peeringrequests.

As indicated at 202 of FIG. 2, in response to client A successfullyinitiating a peering request from private network 110A to privatenetwork 110B, a peering request may be generated for private network110B. In at least some embodiments, generating a peering request mayinvolve displaying a peering request (e.g., as a virtual portrepresentation) on client B's management console (e.g., on clientnetwork 180B) according to the API 104 to the peering service 102. In atleast some embodiments, client B may select the peering request via theAPI 104 to display more information about the request, e.g. to viewinformation about the requesting client and/or the private network fromwhich a peering is being requested. As indicated at 204 of FIG. 2,client B may then accept or reject the peering request via the API 104to the peering service 102 on client B's management console.

At 206 of FIG. 2, if client B accepts the peering request, then asindicated at 208 of FIG. 2 clients A and B may specify routinginformation 122 (e.g., route tables) for the respective virtual ports124 of the peering. The peering service 102 may notify or indicate toclient A that the peering request has been accepted via the API 104 onclient A's management console. For example, in at least someembodiments, if the peering request is accepted by client B, a virtualport representation may be displayed on client A's management console.Similarly, a virtual port representation may be displayed on client B'smanagement console. Thus, the peering between private networks 110A and110B may be represented by virtual port representations on therespective clients' management consoles. Each client may then specifyrouting information 122 for the virtual ports according to the API 104to the peering service 102. In at least some embodiments, specifyingrouting information 122 may involve each client creating a route tablefor the virtual port 124 that indicates a range of one or more privateIP addresses of the respective client private network 110 that are to beadvertised to the other client private network 110 via the virtualpeering indicated by the virtual ports 124, and a range of one or moreprivate IP addresses that are to be accepted via the virtual peeringindicated by the virtual ports 124. FIGS. 3A and 3B illustrate exampleroute tables for a peering as illustrated in FIGS. 1 and 2, according toat least some embodiments. The two clients may exchange this routeinformation 122. As illustrated in FIG. 3C, the subset of private IPaddresses of a client private network 110 that is served by the peeringis the intersection of the range of addresses that the respective clientadvertises for the peering and the range of addresses that the otherclient will accept for the peering.

As indicated at 210 of FIG. 2, after the route tables 122 are defined,private networks 110A and 110B may begin exchanging traffic via anoverlay network path between the virtual ports 124. In at least someembodiments, an instance of an encapsulation layer process, referred toherein as a peering process 120, may be dynamically implemented for eachof the private networks 110A and 110B on one or more computing and/ornetwork devices of the provider network 100. The peering processinstances 120 may serve as an interface between the private networks 110and the overlay network. The peering process instances 120 may be viewedas virtual network transit centers that are used to establish andmaintain peerings between clients' virtual private networks 110. In atleast some embodiments, the virtual ports 124 and route tables 122 thatare established for a peering between private networks 110 may beimplemented as objects within the scope of the peering process instances120. A graphical representation of peering process instances withvirtual ports and routes, and the relationship between the peeringprocess instances and client private networks on a provider network, isshown in FIGS. 1 and 4.

In at least some embodiments, the peering process instance 120associated with a client private network (e.g., peering process instance120A of private network 110A) may receive network packets from theprivate network (e.g., from a router instance on private network 110A)that are to be routed over the network substrate via a virtual peeringpath at the overlay network level (which may be referred to as anoverlay network path) to an address range of another private network(e.g., private network 110B), encapsulate the network packets accordingto an encapsulation protocol of the overlay network, and send theencapsulation packets onto the network substrate to be routed to thepeering process instance 120B of private network 110B according tometadata in the encapsulation packet. The peering process instance 120Bat private network 110B may receive the encapsulation packets,decapsulate the network packets, and provide the decapsulated networkpackets to private network 110B, for example by sending the networkpackets to a router instance on private network 110B for routing totarget private IP addresses of resource instances 112B specified by thenetwork packets. A graphical representation of two peering processinstances that establish and maintain a virtual peering between clientprivate networks on a provider network is shown in FIG. 4.

In at least some embodiments, each encapsulation packet may include one,two, or more network packets. In various embodiments, the encapsulationprotocol may be a standard network protocol such as IPv6 or UserDatagram Protocol (UDP), or alternatively may be a non-standard, custom,or proprietary network protocol. The network packets that areencapsulated according to the encapsulation protocol may, for example,be Internet Protocol (IP) technology packets including but not limitedto IPv4 (Internet Protocol version 4) packets, IPv6 (Internet Protocolversion 6) packets, Transmission Control Protocol (TCP) packets, UserDatagram Protocol (UDP) packets, or Internet Control Message Protocol(ICMP) packets. However, the network packets may be packets according toother IP protocols, other standard protocols than IP protocols, orpackets according to other non-standard, custom, or proprietaryprotocols.

At 206 of FIG. 2, if client B rejects the peering request from client Avia the API 104 to the peering service 102 on client B's managementconsole, then at 212 the peering service 102 may (but does notnecessarily) notify or indicate to client A via the API 104 on clientA's management console that the peering request has been rejected byclient B.

While not shown, in at least some embodiments, the API 104 to thepeering service 102 may allow one or both of the clients that haveestablished a virtual peering between respective client private networks110 to close or terminate the virtual peering via the clients'management consoles. In addition, one or both of the clients may changeor modify the route tables 122 for the virtual peering that were set atelement 208 of FIG. 2 as necessary or desired. If a route table 122 ischanged, the route information may be provided to the other client'speering process instance 120 so that routing for the peering can beadjusted as necessary.

FIGS. 3A and 3B show example route tables for a virtual peering betweenclient private networks on a provider network as illustrated in FIG. 1,according to at least some embodiments. FIG. 3A shows an example routetable 122A that may be created by client A for private network 110A asillustrated in FIG. 1. FIG. 3B shows an example route table 122B thatmay be created by client B for private network 110B as illustrated inFIG. 1. In at least some embodiments, a route table 122 may include anindication of a virtual port 124 at the respective peering processinstance 120 to which address ranges in the table 122 are to be applied(port 124A in route table 122A, port 124B in route table 122B), apeering entity (port 124B in route table 122A, port 124A in route table122B), a range of advertised addresses for the port 124, and a range ofaccepted addresses for the port 124 from the peering entity. In at leastsome embodiments, there may be more than one virtual port 124 defined ata peering process instance 120, and thus the route table 122 for apeering process instance 120 may include more than one entry.

Once the clients establish a peering between two client private networksand generate the respective route tables 122, the peering processinstances 120 may exchange the route information for the peering, asshown in FIG. 1, and use the route information (e.g., route tables 122as shown in FIGS. 3A and 3B) to determine subsets of addresses that areserved by the peering. As illustrated in FIG. 3C, in at least someembodiments, the subset of private IP addresses of a client privatenetwork 110 that is served by the peering is the intersection of therange of addresses that the respective client advertises for the peeringand the range of addresses that the other client will accept for thepeering as defined by the clients' route tables 122. For example, inFIG. 3C, the subset of private IP addresses of client private network110A that is served by the peering is the intersection of the range ofaddresses that client A advertises for the peering via route table 122Aand the range of addresses that client B will accept for the peering asindicated in route table 122B.

FIG. 4 illustrates routing packets between client private networks overa virtual peering path on an overlay network implemented in an exampleprovider network environment, according to at least some embodiments. Inat least some embodiments, the peering process instances 420 on thenetwork substrate 402 of a provider network 400 may use encapsulationprotocol technology to encapsulate and route network packets over thenetwork substrate 402 between client private networks 410 within theprovider network 400. The encapsulation protocol technology may be usedon the network substrate 402 to route encapsulated packets (alsoreferred to as network substrate packets) between endpoints (e.g.,virtual ports 424) on the network substrate 402 via an overlay networkpath or route, referred to in FIG. 4 as a virtual peering path. Theencapsulation protocol technology may be viewed as providing a virtualnetwork topology overlaid on the network substrate 402. In at least someembodiments, the encapsulation protocol technology may include a mappingservice 430 that maintains a mapping directory that maps IP overlayaddresses (public IP addresses) to substrate IP addresses (private IPaddresses) and that may be accessed by various processes on the providernetwork 400, including but not limited to the peering process instances420, for routing packets between endpoints on the network substrate 402.For further information about a virtual network technology that uses anencapsulation protocol to implement an overlay network on a networksubstrate, see FIGS. 9 through 13.

In at least some embodiments, the peering process instance 420associated with a client private network (e.g., peering process instance420A of private network 410A) may receive network packets from theprivate network (e.g., from resource instances 412A via a routerinstance 416A on private network 410A) that are to be routed over thenetwork substrate 402 via a virtual peering path at the overlay networklevel to an address range of another private network (e.g., privatenetwork 410B), encapsulate the network packets according to anencapsulation protocol of the overlay network, and send theencapsulation packets via port 424A onto the network substrate 402 to berouted to port 424B of peering process instance 420B of private network410B according to metadata in the encapsulation packet. The peeringprocess instance 420B at private network 410B may receive theencapsulation packets, decapsulate the network packets, and provide thedecapsulated network packets to private network 410B, for example bysending the network packets to a router instance 416B on private network410B for routing to target private IP addresses of resource instances412B specified by the network packets.

In at least some embodiments, at least some of the resource instances412 on a private network 410 may be implemented according to hardwarevirtualization technology that enables multiple operating systems to runconcurrently on a host computer, i.e. as virtual machines (VMs) on thehost. A hypervisor, or virtual machine monitor (VMM), on a host presentsthe VMs on the host with a virtual platform and monitors the executionof the VMs. Each VM may be provided with one or more private IPaddresses; the VMM on a respective host may be aware of the private IPaddresses of the VMs on the host. Router instance(s) 416 on a privatenetwork 410 may be implemented in any of a variety of ways. A routerinstance 416 on a private network 410 may, for example, be a process onor component of a host system on the provider network 400 such as a hostsystem that implements a VMM and one or more VMs. For example, a routerinstance 416 may be a software process implemented by one or more VMMson the provider network 400 as illustrated in FIG. 10. As anotherexample, a router instance 416 for a private network 410 may beimplemented as or on a resource instance 412 of the private network 410.As yet another example, a router instance 416 for a private network 410may be implemented as or on a physical network device such as a routerdevice or switch device.

As previously mentioned, private networks on a provider network may haveat least partially overlapping private IP address ranges. Embodimentshave been described where clients essentially negotiate non-overlappingportions of their respective address ranges that are to be peered via avirtual peering. In some embodiments, clients may instead negotiate anadditional, separate address space that does not overlap the privateaddress ranges of either private network. This separate address spacemay be referred to as an intermediate address space. Network packetsfrom a private network 410 may then be mapped (e.g., via a networkaddress translation (NAT) service 440) into the intermediate addressspace by the peering process instances 420, or alternatively by themapping service 430, to be delivered to the other private network 410.To the other private network, the packets appear to have originated fromaddresses in the intermediate address space. Return traffic sent to theintermediate addresses from the other private network 410 may be mapped(e.g., via NAT 440) back into the private address space of the targetprivate network 410 for delivery to the correct endpoint.

FIG. 5 illustrates a peering service 502 and API 504 in a providernetwork environment, according to at least some embodiments. A clientassociated with client network 560 may establish, provision, and managea client private network 510A on provider network 500 via one or moreservices of the provider network 500 accessed through a managementconsole 564 on client network 560. The client may access an API 504 of apeering service 502 of provider network 500 via management console 564to establish and manage virtual peerings from client private network510A to other private network(s) 510B on the provider network 500 overthe network substrate of the provider network 500 via peering processinstances 520 at the encapsulation (overlay network) layer of theprovider network 500.

In at least some embodiments, the API 504 to service 502 may display apeering interface 570 on console 564. The peering interface 570 mayprovide one or more graphical and/or textual interface elements thatallow the client to create and manage virtual peerings from the client'sprivate network 510A to other private network(s) 510B on the providernetwork 500. To facilitate the establishment of peerings between privatenetwork 510A on the provider network 500 and the other privatenetwork(s) 510B, the API 504 may provide to the client, via theinterface elements of interface 570, one or more of the followingcapabilities:

-   -   Ability to create and manage virtual port(s) for private network        510A.    -   Ability to create, manage, and modify border routes for the        virtual port(s).    -   Ability to create and manage peerings between virtual port(s) of        private network 510A and virtual port(s) of other private        network(s) 510B.

FIG. 5 shows a non-limiting example of a graphical and/or textualinterface 570 that may be displayed at a client's console 564 forcreating and managing peerings between private networks 510. Theinterface 570 may show a graphical and/or textual representation of apeering process 520A for a particular client private network 510A, forexample as a virtual “transit center” 580. Graphical and/or textualrepresentations of one or more ports 584 in the transit center 580 maybe displayed. Graphical and/or textual representations of one or moreentities 590 (e.g., other private networks 510B) may be shown, as wellas representations of peering(s) between the port(s) 584 and theentity(s) 590. Note that the interface 570 may also show representationsof other aspects of the client's network configuration such as arepresentation of the client private network 510 and one or morecomponents thereof, a representation of the client network 560 and oneor more components thereof, and connections between the client's privatenetwork 510 and network 560.

The client may, for example, use a cursor control device to selectvarious interface elements provided by interface 570 to, for example,create, display, and modify route table(s) 522, to view additionalinformation, for example information 586 about a peering between aparticular port 524 and a particular peering entity 590, and toconfigure various elements such as virtual port(s) 524. The interface570 may include other user interface elements than those shown, forexample menu or other elements that allow the client to select fromamong various ones of the client's private networks, elements to select,create, configure, and manage virtual transit center(s) 580 and port(s)524, elements that allow the client to select or specify target entities590 (e.g., target private networks 510B of other clients) to which theclient wants to establish a peering, and so on.

In at least some embodiments, the API 504 to the peering service 502may, through interface 570, provide one or more interface elements thatallow the client to configure particular ports 524. For example, inaddition to allowing the client to define a route table 582 for avirtual port 524, the client may be allowed to specify a particularnetwork protocol or protocols (e.g., TCP, UDP, ICMP, etc.) that will beused for the virtual peering, specify security protocols for thepeering, specify bandwidth for the peering, and so on. Note at leastsome of the port configuration information may be determined via at anout-of-band negotiation between the respective clients associated withthe private networks 510 that are to be peered, and may then beconfigured for the port(s) 524 of the peering via the API 504.

FIGS. 6A through 6C illustrate some example use cases for virtualpeering between client private networks in a provider networkenvironment, according to at least some embodiments. FIG. 6A shows anexample provider network 600 environment in which a client hasestablished private communications channel between a private gateway 614at client private network 610A and a gateway at an external clientnetwork 660. A virtual peering as described herein may be establishedbetween client private networks 610A and 610B on provider network 600.Client private network 610A may be configured to route at least sometraffic from client private network 610B received over the virtualpeering to endpoints on client network 660 via the private gateway 614and private communications channel, and vice versa. Note that clientprivate networks 610A and 610B and client network 660 may all belong tothe same client, or one or more of the networks may belong to differentclients.

As shown in FIG. 6B, in addition to or instead of a private gateway 614,a client private network 610A may include a public gateway 616 thatenables resources within the client private network 610A to communicatedirectly with external endpoints (e.g., endpoints on client network 660,or endpoints at other clients 680) via an intermediate network 650 suchas the Internet, and vice versa, instead of or in addition to via aprivate communications channel as shown in FIG. 6A. A virtual peering asdescribed herein may be established between client private networks 610Aand 610B on provider network 600. Client private network 610A may beconfigured to route at least some traffic from client private network610B received over the virtual peering to external endpoints via publicgateway 616 and the intermediate network 650, and vice versa. Note thatclient private network 610B may not be provisioned with a public orprivate gateway, and thus resources on private network 610B may only bemade accessible to external endpoints via client private network 610Aand the virtual peering.

FIGS. 1 through 5 show examples where a virtual peering is establishedover a network substrate between two private networks on a providernetwork. However, a service provider may have multiple, geographicallydisperse data centers that each implement a provider network on whichresource instances are implemented and in which client private networksmay be provisioned. FIG. 6C illustrates that, in at least someembodiments, virtual peerings may be established between two clientprivate networks 610 on different provider networks 600. Providernetworks 600A and 600B may be implemented at two geographically dispersedata centers, for example data centers that provide the services of theservice provider to different geographic regions. A virtual peering maybe established between client private network 610A on provider network600A to client private network 610B on provider network 600B. On thevirtual peering, network packets may be routed from client privatenetwork 610A to a router 690A of provider network 600A over a networksubstrate according to an overlay network protocol. The network packetsmay then be routed from the router 690A to a router 690B of providernetwork 600B over an intermediate network 650 such as the Internet.Alternatively, the network packets may be transmitted to router 690B ofprovider network 600B via a private communications channel or via adedicated communications link, for example via a dedicated fiber opticcable that links the two data centers. At provider network 600B, thenetwork packets may be routed from router 690B to client private network610A over a network substrate according to an overlay network protocol.

FIGS. 7A and 7B illustrate example configurations for peerings betweenmultiple client private networks on a provider network, according to atleast some embodiments. In these examples, three client private networks710A, 710B, and 710C have been established on provider network 700. Notethat client private networks 710A, 710B, and 710C may all belong to thesame client, or one or more of the networks 710 may belong to differentclients. Also note that similar configurations may be extended to morethan three private networks 710. In the example shown in FIG. 7A, avirtual peering has been established between client private networks710A and 710B, and another virtual peering has been established betweenclient private networks 710A and 710C. However, there is no peeringbetween 710A and 710C. Client private network 710A may be configured toroute at least some traffic from client private network 710B receivedvia the virtual peering between 710A and 710B to endpoints on clientprivate network 710C via the virtual peering between 710A and 710C, andvice versa. In the example shown in FIG. 7B, a virtual peering has alsobeen established between client private networks 710B and 710C. In thisexample, at least some traffic may be exchanged between 710B and 710Cvia the virtual peering without being routed through 710A.

FIGS. 8A and 8B illustrate example configurations for virtual transitcenters (peering process instances) between client private networks,according to at least some embodiments. In these examples, three clientprivate networks 810A, 810B, and 810C have been established on providernetwork 800. Note that client private networks 810A, 810B, and 810C mayall belong to the same client, or one or more of the networks 810 maybelong to different clients. Also note that similar configurations maybe extended to more than three private networks 810. In both FIGS. 8Aand 8B, a virtual peering has been established between client privatenetworks 810A and 810B, and another virtual peering has been establishedbetween client private networks 810A and 810C. In FIG. 8A, a singlepeering process instance 820A has been created for client privatenetwork 810A to peer with networks 810B and 810C, with two ports 824Aand 824B on peering process instance 820A that are used to peer withnetworks 810B and 810C, respectively. In FIG. 8B, separate peeringprocess instances 820A and 820B have been created for client privatenetwork 810A to peer with networks 810B and 810C, respectively, eachpeering process instance 820 with a port 824 used to peer with arespective client private network 810.

Example Provider Network Environments

This section describes example provider network environments in whichembodiments of the methods and apparatus for private network peering invirtual network environments may be implemented. However, these exampleprovider network environments are not intended to be limiting.

FIG. 9 illustrates an example provider network environment, according toat least some embodiments. A provider network 900 may provide resourcevirtualization to clients via one or more virtualization services 910that allow clients to purchase, rent, or otherwise obtain instances 912of virtualized resources, including but not limited to computation andstorage resources, implemented on devices within the provider network ornetworks in one or more data centers. Private IP addresses 916 may beassociated with the resource instances 912; the private IP addresses arethe internal network addresses of the resource instances 912 on theprovider network 900. In some embodiments, the provider network 900 mayalso provide public IP addresses 914 and/or public IP address ranges(e.g., Internet Protocol version 4 (IPv4) or Internet Protocol version 6(IPv6) addresses) that clients may obtain from the provider 900.

Conventionally, the provider network 900, via the virtualizationservices 910, may allow a client of the service provider (e.g., a clientthat operates client network 950A) to dynamically associate at leastsome public IP addresses 914 assigned or allocated to the client withparticular resource instances 912 assigned to the client. The providernetwork 900 may also allow the client to remap a public IP address 914,previously mapped to one virtualized computing resource instance 912allocated to the client, to another virtualized computing resourceinstance 912 that is also allocated to the client. Using the virtualizedcomputing resource instances 912 and public IP addresses 914 provided bythe service provider, a client of the service provider such as theoperator of client network 950A may, for example, implementclient-specific applications and present the client's applications on anintermediate network 940, such as the Internet. Other network entities920 on the intermediate network 940 may then generate traffic to adestination public IP address 914 published by the client network 950A;the traffic is routed to the service provider data center, and at thedata center is routed, via a network substrate, to the private IPaddress 916 of the virtualized computing resource instance 912 currentlymapped to the destination public IP address 914. Similarly, responsetraffic from the virtualized computing resource instance 912 may berouted via the network substrate back onto the intermediate network 940to the source entity 920.

Private IP addresses, as used herein, refer to the internal networkaddresses of resource instances in a provider network. Private IPaddresses are only routable within the provider network. Network trafficoriginating outside the provider network is not directly routed toprivate IP addresses; instead, the traffic uses public IP addresses thatare mapped to the resource instances. The provider network may includenetwork devices or appliances that provide network address translation(NAT) or similar functionality to perform the mapping from public IPaddresses to private IP addresses and vice versa.

Public IP addresses, as used herein, are Internet routable networkaddresses that are assigned to resource instances, either by the serviceprovider or by the client. Traffic routed to a public IP address istranslated, for example via 1:1 network address translation (NAT), andforwarded to the respective private IP address of a resource instance.

Some public IP addresses may be assigned by the provider networkinfrastructure to particular resource instances; these public IPaddresses may be referred to as standard public IP addresses, or simplystandard IP addresses. In at least some embodiments, the mapping of astandard IP address to a private IP address of a resource instance isthe default launch configuration for all resource instance types.

At least some public IP addresses may be allocated to or obtained byclients of the provider network 900; a client may then assign theirallocated public IP addresses to particular resource instances allocatedto the client. These public IP addresses may be referred to as clientpublic IP addresses, or simply client IP addresses. Instead of beingassigned by the provider network 900 to resource instances as in thecase of standard IP addresses, client IP addresses may be assigned toresource instances by the clients, for example via an API provided bythe service provider. Unlike standard IP addresses, client IP Addressesare allocated to client accounts and can be remapped to other resourceinstances by the respective clients as necessary or desired. A client IPaddress is associated with a client's account, not a particular resourceinstance, and the client controls that IP address until the clientchooses to release it. Unlike conventional static IP addresses, clientIP addresses allow the client to mask resource instance or availabilityzone failures by remapping the client's public IP addresses to anyresource instance associated with the client's account. The client IPaddresses, for example, enable a client to engineer around problems withthe client's resource instances or software by remapping client IPaddresses to replacement resource instances.

FIG. 10 illustrates an example data center that implements an overlaynetwork on a network substrate using IP tunneling technology, accordingto at least some embodiments. A provider data center 1000 may include anetwork substrate that includes networking devices 1012 such as routers,switches, network address translators (NATs), and so on. At least someembodiments may employ an Internet Protocol (IP) tunneling technology toprovide an overlay network via which encapsulated packets may be passedthrough network substrate 1010 using tunnels. The IP tunnelingtechnology may provide a mapping and encapsulating system for creatingan overlay network on a network (e.g., a local network in data center1000 of FIG. 10) and may provide a separate namespace for the overlaylayer (the public IP addresses) and the network substrate 1010 layer(the private IP addresses). Packets in the overlay layer may be checkedagainst a mapping directory (e.g., provided by mapping service 1030) todetermine what their tunnel substrate target (private IP address) shouldbe. The IP tunneling technology provides a virtual network topology (theoverlay network); the interfaces (e.g., service APIs) that are presentedto clients are attached to the overlay network so that when a clientprovides an IP address to which the client wants to send packets, the IPaddress is run in virtual space by communicating with a mapping service(e.g., mapping service 1030) that knows where the IP overlay addressesare.

In at least some embodiments, the IP tunneling technology may map IPoverlay addresses (public IP addresses) to substrate IP addresses(private IP addresses), encapsulate the packets in a tunnel between thetwo namespaces, and deliver the packet to the correct endpoint via thetunnel, where the encapsulation is stripped from the packet. In FIG. 10,an example overlay network tunnel 1034A from a virtual machine (VM)1024A on host 1020A to a device on the intermediate network 1050 and anexample overlay network tunnel 1034B between a VM 1024B on host 1020Band a VM 1024C on host 1020C are shown. In some embodiments, a packetmay be encapsulated in an overlay network packet format before sending,and the overlay network packet may be stripped after receiving. In otherembodiments, instead of encapsulating packets in overlay networkpackets, an overlay network address (public IP address) may be embeddedin a substrate address (private IP address) of a packet before sending,and stripped from the packet address upon receiving. As an example, theoverlay network may be implemented using 32-bit IPv4 (Internet Protocolversion 4) addresses as the public IP addresses, and the IPv4 addressesmay be embedded as part of 128-bit IPv6 (Internet Protocol version 6)addresses used on the substrate network as the private IP addresses.

Referring to FIG. 10, at least some networks in which embodiments may beimplemented may include hardware virtualization technology that enablesmultiple operating systems to run concurrently on a host computer (e.g.,hosts 1020A and 1020B of FIG. 10), i.e. as virtual machines (VMs) 1024on the hosts 1020. The VMs 1024 may, for example, be rented or leased toclients of a network provider. A hypervisor, or virtual machine monitor(VMM) 1022, on a host 1020 presents the VMs 1024 on the host with avirtual platform and monitors the execution of the VMs 1024. Each VM1024 may be provided with one or more private IP addresses; the VMM 1022on a host 1020 may be aware of the private IP addresses of the VMs 1024on the host. A mapping service 1030 may be aware of all network IPprefixes and the IP addresses of routers or other devices serving IPaddresses on the local network. This includes the IP addresses of theVMMs 1022 serving multiple VMs 1024. The mapping service 1030 may becentralized, for example on a server system, or alternatively may bedistributed among two or more server systems or other devices on thenetwork. A network may, for example, use the mapping service technologyand IP tunneling technology to, for example, route data packets betweenVMs 1024 on different hosts 1020 within the data center 1000 network;note that an interior gateway protocol (IGP) may be used to exchangerouting information within such a local network.

In addition, a network such as the provider data center 1000 network(which is sometimes referred to as an autonomous system (AS)) may usethe mapping service technology, IP tunneling technology, and routingservice technology to route packets from the VMs 1024 to Internetdestinations, and from Internet sources to the VMs 1024. Note that anexternal gateway protocol (EGP) or border gateway protocol (BGP) istypically used for Internet routing between sources and destinations onthe Internet. FIG. 10 shows an example provider data center 1000implementing a network that provides resource virtualization technologyand that provides full Internet access via edge router(s) 1014 thatconnect to Internet transit providers, according to at least someembodiments. The provider data center 1000 may, for example, provideclients the ability to implement virtual computing systems (VMs 1024)via a hardware virtualization service and the ability to implementvirtualized data stores 1016 on storage resources 1018 via a storagevirtualization service.

The data center 1000 network may implement IP tunneling technology,mapping service technology, and a routing service technology to routetraffic to and from virtualized resources, for example to route packetsfrom the VMs 1024 on hosts 1020 in data center 1000 to Internetdestinations, and from Internet sources to the VMs 1024. Internetsources and destinations may, for example, include computing systems1070 connected to the intermediate network 1040 and computing systems1052 connected to local networks 1050 that connect to the intermediatenetwork 1040 (e.g., via edge router(s) 1014 that connect the network1050 to Internet transit providers). The provider data center 1000network may also route packets between resources in data center 1000,for example from a VM 1024 on a host 1020 in data center 1000 to otherVMs 1024 on the same host or on other hosts 1020 in data center 1000.

A service provider that provides data center 1000 may also provideadditional data center(s) 1060 that include hardware virtualizationtechnology similar to data center 1000 and that may also be connected tointermediate network 1040. Packets may be forwarded from data center1000 to other data centers 1060, for example from a VM 1024 on a host1020 in data center 1000 to another VM on another host in another,similar data center 1060, and vice versa.

While the above describes hardware virtualization technology thatenables multiple operating systems to run concurrently on host computersas virtual machines (VMs) on the hosts, where the VMs may be rented orleased to clients of the network provider, the hardware virtualizationtechnology may also be used to provide other computing resources, forexample storage resources 1018, as virtualized resources to clients of anetwork provider in a similar manner.

FIG. 11 is a block diagram of an example provider network that providesa storage virtualization service and a hardware virtualization serviceto clients, according to at least some embodiments. Hardwarevirtualization service 1120 provides multiple computation resources 1124(e.g., VMs) to clients. The computation resources 1124 may, for example,be rented or leased to clients of the provider network 1100 (e.g., to aclient that implements client network 1150). Each computation resource1124 may be provided with one or more private IP addresses. Providernetwork 1100 may be configured to route packets from the private IPaddresses of the computation resources 1124 to public Internetdestinations, and from public Internet sources to the computationresources 1124.

Provider network 1100 may provide a client network 1150, for examplecoupled to intermediate network 1140 via local network 1156, the abilityto implement virtual computing systems 1192 via hardware virtualizationservice 1120 coupled to intermediate network 1140 and to providernetwork 1100. In some embodiments, hardware virtualization service 1120may provide one or more APIs 1102, for example a web services interface,via which a client network 1150 may access functionality provided by thehardware virtualization service 1120, for example via a console 1194. Inat least some embodiments, at the provider network 1100, each virtualcomputing system 1192 at client network 1150 may correspond to acomputation resource 1124 that is leased, rented, or otherwise providedto client network 1150.

From an instance of a virtual computing system 1192 and/or anotherclient device 1190 or console 1194, the client may access thefunctionality of storage virtualization service 1110, for example viaone or more APIs 1102, to access data from and store data to a virtualdata store 1116 provided by the provider network 1100. In someembodiments, a virtualized data store gateway (not shown) may beprovided at the client network 1150 that may locally cache at least somedata, for example frequently accessed or critical data, and that maycommunicate with virtualized data store service 1110 via one or morecommunications channels to upload new or modified data from a localcache so that the primary store of data (virtualized data store 1116) ismaintained. In at least some embodiments, a user, via a virtualcomputing system 1192 and/or on another client device 1190, may mountand access virtual data store 1116 volumes, which appear to the user aslocal virtualized storage 1198.

While not shown in FIG. 11, the virtualization service(s) may also beaccessed from resource instances within the provider network 1100 viaAPI(s) 1102. For example, a client, appliance service provider, or otherentity may access a virtualization service from within a respectiveprivate network on the provider network 1100 via an API 1102 to requestallocation of one or more resource instances within the private networkor within another private network.

FIG. 12 illustrates an example provider network that provides privatenetworks on the provider network to at least some clients, according toat least some embodiments. A client's virtualized private network 1260on a provider network 1200, for example, enables a client to connecttheir existing infrastructure (e.g., devices 1252) on client network1250 to a set of logically isolated resource instances (e.g., VMs 1224Aand 1224B and storage 1218A and 1218B), and to extend managementcapabilities such as security services, firewalls, and intrusiondetection systems to include their resource instances.

A client's virtualized private network 1260 may be connected to a clientnetwork 1250 via a private communications channel 1242. A privatecommunications channel 1242 may, for example, be a tunnel implementedaccording to a network tunneling technology or some other technologyover an intermediate network 1240. The intermediate network may, forexample, be a shared network or a public network such as the Internet.Alternatively, a private communications channel 1242 may be implementedover a direct, dedicated connection between virtualized private network1260 and client network 1250.

A public network may be broadly defined as a network that provides openaccess to and interconnectivity among a plurality of entities. TheInternet, or World Wide Web (WWW) is an example of a public network. Ashared network may be broadly defined as a network to which access islimited to two or more entities, in contrast to a public network towhich access is not generally limited. A shared network may, forexample, include one or more local area networks (LANs) and/or datacenter networks, or two or more LANs or data center networks that areinterconnected to form a wide area network (WAN). Examples of sharednetworks may include, but are not limited to, corporate networks andother enterprise networks. A shared network may be anywhere in scopefrom a network that covers a local area to a global network. Note that ashared network may share at least some network infrastructure with apublic network, and that a shared network may be coupled to one or moreother networks, which may include a public network, with controlledaccess between the other network(s) and the shared network. A sharednetwork may also be viewed as a private network, in contrast to a publicnetwork such as the Internet. In embodiments, either a shared network ora public network may serve as an intermediate network between a providernetwork and a client network.

To establish a virtualized private network 1260 for a client on providernetwork 1200, one or more resource instances (e.g., VMs 1224A and 1224Band storage 1218A and 1218B) may be allocated to the virtualized privatenetwork 1260. Note that other resource instances (e.g., storage 1218Cand VMs 1224C) may remain available on the provider network 1200 forother client usage. A range of public IP addresses may also be allocatedto the virtualized private network 1260. In addition, one or morenetworking devices (routers, switches, etc.) of the provider network1200 may be allocated to the virtualized private network 1260. A privatecommunications channel 1242 may be established between a private gateway1262 at virtualized private network 1260 and a gateway 1256 at clientnetwork 1250.

In at least some embodiments, in addition to, or instead of, a privategateway 1262, virtualized private network 1260 may include a publicgateway 1264 that enables resources within virtualized private network1260 to communicate directly with entities (e.g., network entity 1244)via intermediate network 1240, and vice versa, instead of or in additionto via private communications channel 1242.

Virtualized private network 1260 may be, but is not necessarily,subdivided into two or more subnetworks, or subnets, 1270. For example,in implementations that include both a private gateway 1262 and a publicgateway 1264, the private network may be subdivided into a subnet 1270Athat includes resources (VMs 1224A and storage 1218A, in this example)reachable through private gateway 1262, and a subnet 1270B that includesresources (VMs 1224B and storage 1218B, in this example) reachablethrough public gateway 1264.

The client may assign particular client public IP addresses toparticular resource instances in virtualized private network 1260. Anetwork entity 1244 on intermediate network 1240 may then send trafficto a public IP address published by the client; the traffic is routed,by the provider network 1200, to the associated resource instance.Return traffic from the resource instance is routed, by the providernetwork 1200, back to the network entity 1244 over intermediate network1240. Note that routing traffic between a resource instance and anetwork entity 1244 may require network address translation to translatebetween the public IP address and the private IP address of the resourceinstance.

At least some embodiments may allow a client to remap public IPaddresses in a client's virtualized private network 1260 as illustratedin FIG. 12 to devices on the client's external network 1250. When apacket is received (e.g., from network entity 1244), the network 1200may determine that the destination IP address indicated by the packethas been remapped to an endpoint on external network 1250 and handlerouting of the packet to the respective endpoint, either via privatecommunications channel 1242 or via the intermediate network 1240.Response traffic may be routed from the endpoint to the network entity1244 through the provider network 1200, or alternatively may be directlyrouted to the network entity 1244 by the client network 1250. From theperspective of the network entity 1244, it appears as if the networkentity 1244 is communicating with the public IP address of the client onthe provider network 1200. However, the network entity 1244 has actuallycommunicated with the endpoint on client network 1250.

While FIG. 12 shows network entity 1244 on intermediate network 1240 andexternal to provider network 1200, a network entity may be an entity onprovider network 1200. For example, one of the resource instancesprovided by provider network 1200 may be a network entity that sendstraffic to a public IP address published by the client.

FIG. 13 illustrates subnets and security groups in an example virtualprivate network implementation on a provider network, according to atleast some embodiments. In at least some embodiments, a provider networksuch as provider network 1200 in FIG. 12 may allow the client toestablish and manage virtual security groups 1316 within the client'svirtual private network 1310, within or across subnets 1314. A securitygroup 1316 acts as a firewall that controls the traffic allowed to reachone or more resource instances 1318 within the security group 1316. Theclient may establish one or more security groups 1316 within the privatenetwork 1310, and may associate each resource instance 1318 in theprivate network 1310 with one or more of the security groups 1316. In atleast some embodiments, the client may establish and/or modify rules foreach security group 1316 that control the inbound traffic allowed toreach the resource instances 1318 associated with the security group1316.

In the example virtual private network 1310 shown in FIG. 13, theprivate network 1310 is subdivided into two subnets 1314A and 1314B.Access to the private network 1310 is controlled by gateway(s) 1330.Each subnet 1314 may include at least one router 1312 that acts to routetraffic to (and from) resource instances 1318 on the respective subnet1314. In the example shown in FIG. 13, resource instances 1318A through1318E are on subnet 1314A, and resource instances 1318F through 1318Jare on subnet 1314B. The client has established four security groups1316A through 1316D. As shown in FIG. 13, a security group may extendacross subnets 1314, as does security group 1316A that includes resourceinstances 1318A and 1318B on subnet 1314A and resource instance 1318F onsubnet 1314B. In addition, a resource instance 1318 may be included intwo or more security groups 1316, as is resource instance 1318A which isincluded in security group 1316A and 1316B.

Illustrative System

In at least some embodiments, a server that implements a portion or allof the methods and apparatus for private network peering in virtualnetwork environments as described herein may include a general-purposecomputer system that includes or is configured to access one or morecomputer-accessible media, such as computer system 2000 illustrated inFIG. 14. In the illustrated embodiment, computer system 2000 includesone or more processors 2010 coupled to a system memory 2020 via aninput/output (I/O) interface 2030. Computer system 2000 further includesa network interface 2040 coupled to I/O interface 2030.

In various embodiments, computer system 2000 may be a uniprocessorsystem including one processor 2010, or a multiprocessor systemincluding several processors 2010 (e.g., two, four, eight, or anothersuitable number). Processors 2010 may be any suitable processors capableof executing instructions. For example, in various embodiments,processors 2010 may be general-purpose or embedded processorsimplementing any of a variety of instruction set architectures (ISAs),such as the x86, PowerPC, SPARC, or MIPS ISAs, or any other suitableISA. In multiprocessor systems, each of processors 2010 may commonly,but not necessarily, implement the same ISA.

System memory 2020 may be configured to store instructions and dataaccessible by processor(s) 2010. In various embodiments, system memory2020 may be implemented using any suitable memory technology, such asstatic random access memory (SRAM), synchronous dynamic RAM (SDRAM),nonvolatile/Flash-type memory, or any other type of memory. In theillustrated embodiment, program instructions and data implementing oneor more desired functions, such as those methods, techniques, and datadescribed above for private network peering in virtual networkenvironments, are shown stored within system memory 2020 as code 2025and data 2026.

In one embodiment, I/O interface 2030 may be configured to coordinateI/O traffic between processor 2010, system memory 2020, and anyperipheral devices in the device, including network interface 2040 orother peripheral interfaces. In some embodiments, I/O interface 2030 mayperform any necessary protocol, timing or other data transformations toconvert data signals from one component (e.g., system memory 2020) intoa format suitable for use by another component (e.g., processor 2010).In some embodiments, I/O interface 2030 may include support for devicesattached through various types of peripheral buses, such as a variant ofthe Peripheral Component Interconnect (PCI) bus standard or theUniversal Serial Bus (USB) standard, for example. In some embodiments,the function of I/O interface 2030 may be split into two or moreseparate components, such as a north bridge and a south bridge, forexample. Also, in some embodiments some or all of the functionality ofI/O interface 2030, such as an interface to system memory 2020, may beincorporated directly into processor 2010.

Network interface 2040 may be configured to allow data to be exchangedbetween computer system 2000 and other devices 2060 attached to anetwork or networks 2050, such as other computer systems or devices asillustrated in FIGS. 1 through 13, for example. In various embodiments,network interface 2040 may support communication via any suitable wiredor wireless general data networks, such as types of Ethernet network,for example. Additionally, network interface 2040 may supportcommunication via telecommunications/telephony networks such as analogvoice networks or digital fiber communications networks, via storagearea networks such as Fibre Channel SANs, or via any other suitable typeof network and/or protocol.

In some embodiments, system memory 2020 may be one embodiment of acomputer-accessible medium configured to store program instructions anddata as described above for FIGS. 1 through 13 for implementingembodiments of private network peering in virtual network environments.However, in other embodiments, program instructions and/or data may bereceived, sent or stored upon different types of computer-accessiblemedia. Generally speaking, a computer-accessible medium may includenon-transitory storage media or memory media such as magnetic or opticalmedia, e.g., disk or DVD/CD coupled to computer system 2000 via I/Ointerface 2030. A non-transitory computer-accessible storage medium mayalso include any volatile or non-volatile media such as RAM (e.g. SDRAM,DDR SDRAM, RDRAM, SRAM, etc.), ROM, etc, that may be included in someembodiments of computer system 2000 as system memory 2020 or anothertype of memory. Further, a computer-accessible medium may includetransmission media or signals such as electrical, electromagnetic, ordigital signals, conveyed via a communication medium such as a networkand/or a wireless link, such as may be implemented via network interface2040.

CONCLUSION

Various embodiments may further include receiving, sending or storinginstructions and/or data implemented in accordance with the foregoingdescription upon a computer-accessible medium. Generally speaking, acomputer-accessible medium may include storage media or memory mediasuch as magnetic or optical media, e.g., disk or DVD/CD-ROM, volatile ornon-volatile media such as RAM (e.g. SDRAM, DDR, RDRAM, SRAM, etc.),ROM, etc, as well as transmission media or signals such as electrical,electromagnetic, or digital signals, conveyed via a communication mediumsuch as network and/or a wireless link.

The various methods as illustrated in the Figures and described hereinrepresent exemplary embodiments of methods. The methods may beimplemented in software, hardware, or a combination thereof. The orderof method may be changed, and various elements may be added, reordered,combined, omitted, modified, etc.

Various modifications and changes may be made as would be obvious to aperson skilled in the art having the benefit of this disclosure. It isintended to embrace all such modifications and changes and, accordingly,the above description to be regarded in an illustrative rather than arestrictive sense.

What is claimed is:
 1. A provider network, comprising; a networksubstrate; a plurality of host devices implementing a plurality ofresource instances for clients of the provider network, wherein subsetsof the resource instances are provisioned in virtual networks for theclients on the provider network; one or more computing devicesimplementing a peering service, wherein the one or more computingdevices implementing the peering service are configured to: determinerouting information for routing network packets between one or moreresource instances of a first virtual network and one or more resourceinstances of another virtual network via a peering on the providernetwork; and enable the first virtual network and the other virtualnetwork to exchange network packets via the peering on the providernetwork, wherein the packets are addressed to respective private IPaddresses of the first virtual network or the other virtual network whenbeing transmitted from a resource instance of the first virtual networkor the other virtual network.
 2. The provider network as recited inclaim 1, wherein, to establish the peering on the provider network, theone or more computing devices implementing the peering service arefurther configured to: establish a first virtual port for the firstvirtual network and another virtual port for the other virtual network;and obtain, via an application programming interface (API) from a firstclient and another client, routing information for the first virtualport and the other virtual port, respectively.
 3. The provider networkas recited in claim 2, wherein the routing information for a givenvirtual port indicates a range of private IP addresses of the respectivevirtual network that are advertised from the given virtual port and arange of private IP addresses that are accepted at the given virtualport.
 4. The provider network as recited in claim 3, wherein a subset ofprivate IP addresses that is served by the peering on the providernetwork for a given virtual network is the intersection of the range ofprivate IP addresses that are advertised from the respective virtualport and the range of private IP addresses that are accepted at theother virtual port of the peering on the provider network.
 5. Theprovider network as recited in claim 1, wherein, to establish thepeering on the provider network, the one or more computing devicesimplementing the peering service are configured to: establish a firstpeering process instance for the first virtual network; and establishanother peering process instance for the other virtual network; whereinthe first peering process instance and the other peering processinstance are configured to exchange the network packets over the networksubstrate according to an overlay network protocol.
 6. The providernetwork as recited in claim 5, wherein, to exchange the network packetsover the network substrate according to the overlay network protocol,one or more computing devices implementing each peering process instanceare configured to: receive network packets from the first virtualnetwork or the other virtual network; encapsulate the network packetsaccording to an encapsulation protocol to generate encapsulationpackets; and send the encapsulation packets onto the network substrateto be routed to the peering process instance or the other peeringprocess instance according to routing information in the encapsulationpackets.
 7. The provider network as recited in claim 6, wherein, toexchange the network packets over the network substrate according to theoverlay network protocol, the one or more computing devices implementingthe first peering process instance or the other peering process instanceare further configured to: receive encapsulated packets from the peeringprocess instance or the other peering process instance; decapsulate thenetwork packets from the received encapsulated packets; and send thedecapsulated network packets to the first virtual network or the othervirtual network for routing to endpoints on the first virtual network orfor routing to endpoints on the other virtual network.
 8. A method,comprising: provisioning, on a provider network, a plurality of resourceinstances for clients of the provider network, wherein subsets of theresource instances are provisioned in virtual networks of the clientshosted by the provider network; determining, by a peering serviceimplemented on one or more computing devices in the provider network,routing information for routing network packets between one or moreresource instances of a first virtual network and one or more resourceinstances of another virtual network; and exchanging network packetsbetween the first virtual network and the other virtual network over apeering on a network substrate of the provider network, wherein thepackets are addressed to respective private IP addresses of the firstvirtual network or the other virtual network when being transmitted froma resource instance of the first virtual network or the other virtualnetwork.
 9. The method as recited in claim 8, further comprising:obtaining, by the peering service, a request from the first virtualnetwork to open the peering to the other virtual network; providing, bythe peering service, to the other virtual network, an indication of thepeering request from the first virtual network; and establishing thepeering on the network substrate of the provider network between thefirst virtual network and the other virtual network, in response to anindication that the peering request from the first virtual network isaccepted by the other virtual network.
 10. The method as recited inclaim 9, wherein said establishing the peering between the first virtualnetwork and the other virtual network over the network substrate of theprovider network comprises: establishing a peering process instance forthe first virtual network and another peering process instance for theother virtual network; establishing a virtual port for the first virtualnetwork at the peering process instance and another virtual port for theother virtual network at the other peering process instance; andestablishing the peering between the virtual ports over the networksubstrate according to an overlay network protocol.
 11. The method asrecited in claim 10, wherein said exchanging the network packets betweenthe first virtual network and the other virtual network over the peeringon the network substrate comprises: receiving network packets at thepeering process instance from the first virtual network; encapsulatingthe network packets according to an encapsulation protocol to generateencapsulation packets; and sending the encapsulation packets via thevirtual port onto the network substrate to be routed to the othervirtual port at the other peering process instance according to routinginformation in the encapsulation packets.
 12. The method as recited inclaim 10, wherein said exchanging the network packets between the firstvirtual network and the other virtual network over the peering on thenetwork substrate comprises: receiving encapsulated packets at thevirtual port of the peering process instance; decapsulating networkpackets from the received encapsulated packets; and providing thedecapsulated network packets to the virtual network for routing,according to private IP addresses, to endpoints on the virtual network.13. The method as recited in claim 10, further comprising: establishinganother virtual port for the first virtual network at the peeringprocess instance; and establishing another peering between the firstvirtual network and a third virtual network at the other virtual port.14. The method as recited in claim 9, further comprising providing, bythe peering service, an application programming interface (API) to theclients, wherein said obtaining, said providing, and said establishingare performed according to the API.
 15. The method as recited in claim8, wherein said exchanging the network packets between the first virtualnetwork and the other virtual network over the peering on the networksubstrate comprises translating private network addresses from privateaddress spaces of the first virtual network and the other virtualnetwork into an intermediate address space for delivery over thepeering.
 16. The method as recited in claim 8, wherein the other virtualnetwork is on a different provider network implemented in a separatedata center.
 17. A non-transitory computer-accessible storage mediumstoring program instructions, that when executed on one or moreprocessors, cause the one or more processors to implement a peeringservice in a provider network, wherein the program instructions whenexecuted on the one or more processors cause the peering service to:provide an application programming interface (API) to clients of theprovider network, wherein subsets of a plurality of resource instanceson the provider network are provisioned in virtual networks for theclients on the provider network; and based on a peering between a firstvirtual network and another virtual network being requested via the APIof the peering service: determine routing information for routingnetwork packets between the first virtual network and the other virtualnetwork; and enable the first virtual network and the other virtualnetwork to exchange network packets between the first virtual networkand the other virtual network via the peering between the first virtualnetwork and the other virtual network, wherein the network packets areaddressed to respective private IP addresses of the first virtualnetwork or the other virtual network when being transmitted from aresource instance of the first virtual network or the other virtualnetwork.
 18. The non-transitory computer-accessible storage medium asrecited in claim 17, wherein, to establish the peering on the providernetwork, the program instructions when executed on the one or moreprocessors further cause the peering service to: establish a firstvirtual port for the first virtual network and another virtual port forthe other virtual network; and obtain routing information for the firstvirtual port and the other virtual port, wherein the routing informationfor each virtual port indicates a range of addresses that are advertisedfrom the respective virtual port and a range of addresses that areaccepted at the respective virtual port.
 19. The non-transitorycomputer-accessible storage medium as recited in claim 17, wherein, toestablish the peering on the provider network, the program instructionswhen executed on the one or more processors further cause the peeringservice to: establish a first peering process instance for the firstvirtual network and another peering process instance for the othervirtual network; establish a first virtual port for the first virtualnetwork at the first peering process instance and another virtual portfor the other virtual network at the other peering process instance; andestablish the peering between the first virtual port and the othervirtual port over the network substrate.
 20. The non-transitorycomputer-accessible storage medium as recited in claim 19, wherein thefirst peering process instance and the other peering process instanceare established at an encapsulation layer of the network substrate, andwherein the first peering process instance and the other peering processinstance are configured to exchange traffic between the first virtualnetwork and the other virtual network over the network substrate via thepeering according to an encapsulation protocol.